Lecture 5

Question 1

Which organisms have 80S ribosomes?

Answer 1

Eukaryotes

Question 2

Which organisms have 70S ribosomes?

Answer 2

Eukaryotes and Prokaryotes

Question 3

What subunits are used in 80S ribosomes?

Answer 3

40S and 60S

Question 4

What subunits are used in 70S ribosomes?

Answer 4

30S and 50S

Question 5

Why do Eukaryotes have 70S ribosomes too?

Answer 5

Endosymbiont Theory

Question 6

What organisms have nucleoids?

Answer 6

Prokaryotes, where plasmids are located

Question 7

What organisms have endospores?

Answer 7

Prokaryotes

Question 8

Which internal bacterial structures make good antibiotic targets?

Answer 8

• 70S ribosomes
• Nucleoids

Question 9

How does endosymbiont theory relate to antibiotic targeting?

Answer 9

Because mitochondria and chloroplasts are both used as energy sources, antibiotic targeting has to focus on selectively targeting prokaryote DNA/RNA in order to not attack these crucial structures.

Question 10

What is the first step of endospore formation?

Answer 10

Axial filament formation

Question 11

What is the second step of endospore formation?

Answer 11

Septum formation - spore with some DNA separates from main body

Question 12

What is the third step in endospore formation?

Answer 12

Engulfment of forespore - spore takes rest of the DNA and the plasma membrane is swallowed by the main body

Question 13

What is the fourth step of endospore formation?

Answer 13

Cortex formation - peptidoglycan cortex forms around spore

Question 14

What is the fifth step of endospore formation?

Answer 14

Coat synthesis - Keratin and protein coat synthesized around cortex (Exosporium also starts forming around coat)

Question 15

What is the sixth step of endospore formation?

Answer 15

Completion of coat synthesis + increase in refactility and heat resistance

Question 16

What is the seventh step of endospore formation?

Answer 16

Lysis of sporangium, spore liberation

Question 17

What causes spores to form?

Answer 17

Occurs due to lack of food or heating

Question 18

What is dipicolinic acid?

Answer 18

It plays a role in heat resistance in bacterial endospores

Question 19

Why are endospores heat resistance?

Answer 19

• Calcium-dipicolinic acid stabiliation of DNA
• Core dehydration

Question 20

What are the stages of germination?

Answer 20

1. Activation (triggered by heating)
2. Germination (triggered by food)
3. Outgrowth, protoplast makes new cell components and vegetative cell emerges from the spore

Question 21

What are inclusion bodies?

Answer 21

Granules, crystals or globules in the cytoplasm that are enclosed by single layer membranes and used for storage.

Question 22

Organic inclusion bodies

Answer 22

• Glycogen granules
• Cyanophycin granules
• Carboxysomes
• Gas vacuoles

Question 23

Inorganic inclusion bodies

Answer 23

• Polyphosphate granules
• Magnetasomes

Question 24

Which of the following can you find in a bacterial cell? Nucleus, Golgi apparatus, Endoplasmic reticulum, peptidoglycan, lysosome, ribosome (70S, 80S), cytoskeleton, DNA

Answer 24

• Peptidoglycan
• 70S ribosome
• Cytoskeleton
• DNA

Question 25

Sporulation is a method of bacterial reproduction:

Answer 25

FALSE - it is a form of protection until conditions improve

Question 26

Spore forming genera

Answer 26

- Clostridium - Bacillus - Sporosarcina (cocci)

Question 27

Famous spore former diseases

Answer 27

- Bacillus: anthrax and food poisoning - Clostridium: botulism, tetanus and gas gangrene

Question 28

What is a cytoplasmic matrix?

Answer 28

Another term for cytosol

Question 29

What are the four locations for endospore formation?

Answer 29

- terminal - subterminal - central - terminal with swollen sporangium

Question 30

What is endospore formation called?

Answer 30

Sporogenesis (sporulation)

Question 31

What is a protoplast?

Answer 31

A cell that has its cell wall partially or completely removed